1. Field of the Invention
The invention relates to a method for operating a door operator and a door operator.
2. Related Art
EP 0 756 663 B1 describes a mechanical door operator. A cam plate unit, which partially passes through a spring, is supported in a cylindrical housing of the door operator. On one side, this spring is bearing against a projection in the housing, and, on the other side, against a shoulder of the cam plate unit. Furthermore, the door operator is equipped with a drive shaft to which the door leaf to be moved is connected. The drive shaft presents an eccentrically shaped cam disc within the housing. This cam disc is placed between two rollers, which are disposed at the cam plate unit and act as supports, respectively as a pressure element. On account of the eccentricity of the cam disc, a movement of the drive shaft results in a longitudinal movement of the cam plate unit.
In addition to the described mechanical door operators, furthermore, electro-mechanical door operators are utilized. The mentioned operators have an electro-mechanical system that can be utilized for opening and/or closing a door. Integrated control circuits are being used for controlling the electrical components of the door operator. Thus, it is for example possible to appropriately program the integrated control circuits.
From the state-of-the-art it is known that door operators are able to perform a plurality of functions. Depending on the application, it has proven to be advantageous if one of the following functions can be initiated at the door:                emergency stop function,        “automatically open”, or        “push-and-go” function.        
By completing a door operator with the above mentioned functions, it is possible to employ said door operator where special applications are required, such as in a hospital. A nurse is thus in the position to activate a “push-and-go” function by touching the door, which results in an automatic opening of the door. However, it has proven not to be necessary to equip each door operator with the entire range of possible functions. On the contrary, a basic module of a known door operator is equipped with functional modules, which allow for performing the respectively desired function. In this case, it has proven to be disadvantageous that the door operators are prone to failure and become more expensive, when utilizing a plurality of fitted functional modules. In addition, restrictions in the number of possible functions that can be realized by the door operator result from the limited number of functional modules that can be fitted on. Moreover, the plurality of functional modules requires to provide a relatively large structural space, which otherwise remains unutilized.